Re: "Scheme has data types and Lisp doesn't."

I hope someone here can explain the origin of this notion that
"Scheme has data types and Lisp doesn't". I have heard several
people make this claim over the past couple of years, but never
with any concrete evidence nor even a clear explanation of what
it's supposed to mean. (It was usually in almost exactly those
words, however.)
I know a modest amount about these languages and have access to
references on them. I have not been able figure out what it is
supposed to mean.
Most recently, in a discussion of which functional programming
language should be taught to students (not at UNC, by the way)
I heard that Scheme was to be preferred because compiled Scheme
executes much faster than compiled Common Lisp. The reason for
that difference? Because, of course, "Scheme has data types
and Lisp doesn't."